Discussed general structure and function of animals, had the class come up with examples of how structures on animals can be explained by their function. Eventually geared the discussion more towards water animals because this applies more to what their final project will be. For the last 20 minutes divided class into groups of 3 to choose one animal per group and do a design on paper of their Lego model.
This activity did not have enough "meat" and we had to stretch out the activities for longer than they should have taken. As a result the class started to lose interest a little bit toward the end of the class period. If you end up using this activity it would be a good idea to try and incorporate Legos toward the end of the class or add more to the discussion to make it more interesting.